Sam James <s...@gentoo.org> writes: > I just hit this in a fascinating place. > > When working on xz, I set `-Werror=suggest-attribute=returns_nonnull`, and > the build failed (as I expected it to), but with no visible error from > the compiler. > > There's a mysterious '>/dev/null 2>&1' on the second line where > liblzma_la-common.o is built without PIC. > > With -fPIC, IPA doesn't end up doing attribute discovery. Without it, > it does. This behaviour is insane and we should patch it out. > > Bug: https://bugs.gentoo.org/135865 > Cc: glaub...@physik.fu-berlin.de > Signed-off-by: Sam James <s...@gentoo.org> > --- > Please consider this kind of a PoC for discussion. This came up on the > GCC bug tracker the other day which prompted me to post it and get people's > opinions. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55212#c158.
(Also, if we agree the idea is fine, I'll improve the commit message -- it was just written out of exasperation for a local patchset when I was debugging something and going mad, sorry!) > > libtool assumes that the warning output with vs without -fPIC is going > to be identical, hence the non-PIC build output should be completely > suppressed. > > I think this is a premature optimization at best, and it's caused real > confusion to people. Can we drop it? > > If this looks OK, I can check more closely if I need to remove more > bits. > > build-aux/ltmain.in | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/build-aux/ltmain.in b/build-aux/ltmain.in > index 63377541..48e89042 100644 > --- a/build-aux/ltmain.in > +++ b/build-aux/ltmain.in > @@ -1665,8 +1665,6 @@ compiler." > func_append command " -o $obj" > fi > > - # Suppress compiler output if we already did a PIC compilation. > - func_append command "$suppress_output" > func_show_eval_locale "$command" \ > '$opt_dry_run || $RM $removelist; exit $EXIT_FAILURE' > > > base-commit: 22a7e547e9857fc94fe5bc7c921d9a4b49c09f8e
